Since the enforcement of the “Montreal Protocol on Substances that Deplete the Ozone Layer”, which was signed in 1987 as the result of concerns of the international community on issues about ozone layer, Halon fire-extinguishing agent series, which account for more that ⅓ of the total amounts of ozone depleting chemicals used in fire-fighting industry, are gradually substituted by new kinds of fire-extinguishing products that are environment-friendly or relatively friendly. In recent years, the aerosol fire-extinguishing apparatus developed is a typical apparatus in the field of gas fire-extinguishing, this aerosol product is increasingly appreciated in fire-fighting industry and by research & development departments due to its advantages of no damage to ozone layer, no greenhouse effect entailed, no pollution to the environment, and superiority over fire-fighting apparatuses with gases such as trifluoromethane, heptafluoropropane and carbon dioxide and the like by producing innocuous substances which are harmless to people and have little damage to the object protected from fire, as well as high fire-suppression efficiency and so on. Particularly, the third generation aerosol fire-extinguishing apparatus, charged with aerosol generating agent including 35%-50% strontium nitrate and 10%-20% potassium nitrate, overcomes the defects that the insulation capability of the object to be protected from fire will decrease after applying the fire-extinguishing agent contained in the second generation aerosol fire-extinguishing apparatus charged with more than 30% potassium nitrate. Moreover, the third generation aerosol fire-extinguishing apparatus also has the advantages of non-corrosiveness, moisture-resistance and non-electric conduction. Therefore, it is becoming a popular concern in the industry of fire-fighting apparatus production, research and development all over the world.
In the prior art before the disclosure of the present invention, the efficiency of fire-suppression is the target pursued in the design of the fire-extinguishing apparatus in fire-extinguishing industry, which is improved mainly in terms of the design of the fire-extinguishing agent. Different fire-extinguishing agents have different fire-extinguishing mechanisms, resulting in different designs of fire-extinguishing apparatuses. The object of fire extinguishing can be achieved by eliminating or reducing any one or two of the following conditions necessary for combustion, i.e. (1) density of the combustible substance; (2) oxygen content; (3) ignition heat; (4) unrestrained chain reaction. At present, according to different installation manners, the present fire-extinguishing apparatuses can be mainly classified into two types, i.e. floor standing type and suspended type. Several kinds of fire-extinguishing apparatuses have been disclosed in published patent documents, which include patent ZL97248609.7, patent application 9912556.4 and patent ZL01277738.2 owned by Shanxi Anhua Extinguishing Apparatus Co. Ltd., patent ZL02262244.6 owned by Xi'an Xinzhu Fire & Rescue Equipment Limited Company, and patent application 200510082726.5 filed by Beijing Institute of Technology. Although the double-shell structure of the apparatus disclosed in ZL97248609.7 has some positive effect in reducing the temperature of the shell surface, it has the disadvantages of low space-effectiveness due to its huge and bulky body, and the designs described therein for heat-absorbing and fire-inhibiting are relatively simple. The apparatuses disclosed in patent application 9912556.4 and patent ZL01277738.2 both have shutter-type sprayers and are respectively provided with baffle plates, fire-retardant and temperature regulating rods and meshworks, and retardant blocks, which have positive effect on aerosol temperature reduction and uniform spray thereof, and, however, have no improvement in the combustion speed. The apparatus disclosed in patent ZL02262244.6 adopts a double-layer structure and is provided with a complete oxidation chamber and a metal meshwork, which only aims to solve the issues about cooling, filtration and outlet temperature of aerosol. The apparatus disclosed in the patent application 200510082726.5 uses the admixture of aerosol and dry-powder as fire-extinguishing agent, and has chemical and physical cooling chambers, which makes it possible to put out a fire by means of both aerosol and dry-powder. However, due to the addition of dry-powder, the fire-extinguishing apparatus can only be referred to as an apparatus designed for unclean fire-extinguishing agent.
In addition to the important factor such as the design of the fire-extinguishing agent, i.e. the composition of the fire-extinguishing agent, considering the structure design of the apparatus, the fire-suppression efficiency of the aerosol fire-extinguishing apparatus depends on several further factors, such as spraying time, temperature of the sprayer, process and condition of the spraying, and surface temperature of the fire-extinguishing apparatus. Wherein, the spraying time (which refers to, after the actuation of the fire-extinguishing apparatus, the time duration starting from the spray of aerosol fire-extinguishing agent from spray nozzle to the stop thereof, which according to the standard of GA499.1-2004, is no more than 120 s under the experimental temperature of 20° C.±5° C.) is the key factor affecting the fire-suppression efficiency of the apparatus. The above-mentioned various apparatuses of prior art are designed substantially according to the design solution of the fire-extinguishing agent, and in most cases, the spraying time of the apparatuses cannot be controlled intentionally and it is difficult to meet the technical requirement that the spraying time should be less than 120 s.